From: Michael Briley (mike_at_maxwell.phys.uwosh.edu)
Date: Sun Apr 10 2005 - 08:25:52 PDT
Hi Ed,
You have to have better coordinates as inputs. One second of latitude
is about 100 feet! Also, going by your descriptions, I'm not sure the
input lat/long values were spot on. I've taken the liberty of looking
them up myself and the values below lead to a useable solution.
Whether it's the correct solution depends on my getting the streets
right and your measurements of the corresponding pixel locations.
> Calibration Point 3 (Upper Lft ref pt) --La Luna Dr & Unk dead end
road
> Lat 34 26 17 (North)
> Long -119 17 17 (West)
> Pixel coordinates (r/d) 90/29
lat: 34 26 16.47
log: -119 17 20.57
The dead end road is Oakwood. Your point is about 90 feet northeast
of Oakwood & Cottonwood.
> Calibration Point 1 (Lft ref pt) -rte 33 & villanova rd
> Lat 34 25 33 (North)
> Long -119 17 17 (West)
> Pixel coordinates (r/d) 91/387
(assuming west Intersection of 33 & Villanova:)
lat: 34 25 32.70
log: -119 17 20.42
Your coords are nearer the intersection of Old Grade Rd. & Villanova.
> Calibration Point 2 (Lower Rt ref point) villanova rd & unk rd
> Lat 34 25 46 (North)
> Long -119 16 21 (West)
> Pixel coordinates (r/d) 454/276
(assuming unknown road is Rancho La Vista:)
lat: 34 25 46.55
log: -119 16 25.94
Your coords are about 430 feet east of this point and a few feet off
the road (i.e., this one was way off).
One trick for neighborhood maps, especially if your map software
isn't precise, is to actually go to the reference points with the GPS
and get the coordinates that way. You can be sure they're accurate then!
I hope this helps,
-Mike
-- This is the NewtonTalk list - http://www.newtontalk.net/ for all inquiries Official Newton FAQ: http://www.chuma.org/newton/faq/ WikiWikiNewt for all kinds of articles: http://tools.unna.org/wikiwikinewt/
This archive was generated by hypermail 2.1.5 : Sun Apr 10 2005 - 09:30:00 PDT